6.6 The controller

Outcome 6 of 8 in domain 6 · Power, panels, packs, motors, converters

H-bridge, three-phase inverter, Hall sensors, sensorless control, FOC.

My targets

I declare:

Draw an H-bridge, explain the four switches, dead time, and drive a brushed motor both ways.
Draw the three-phase inverter of a brushless controller and explain six-step commutation with Hall sensors.
Explain sensorless control (back-EMF) and why it struggles at start-up.
Say what field-oriented control (FOC) adds and why recent e-bikes are silent.
Open a bike or tool controller, spot the MOSFETs, gate drivers, shunt and microcontroller, and follow the power path.
Measure a controller’s phase current and battery current and explain why they differ.
Drive a hobby servo and an electronic speed controller (ESC) from a microcontroller, and explain the signal they expect.
Diagnosis: a controller that cuts out on acceleration, current limit, pack voltage sag or tired MOSFET; the three measurements.